AIO (All In One) Vacuum Furnaces with Intensive Analysis and Test System

9 August 2022

Do you know that you can save time with AIO LPC Furnaces, which bear Sistem Teknik’s signature, with high energy efficiency? We have examined the high technology AIO LPC Furnaces for you that give repeatable results at the end of each process.

There are many kinds of heat treatment techniques which allow to get better quality for certain kind of steel. With develop- ing technology, these techniques require specialization for the usage area. Especially, aviation and de- fence industry have a certain crite- rion which demands special expe- rience on this field. Sistem Teknik Industrial Furnaces comes to the fore on that kind of applications, specialized with the processes which includes vacuum. As a result of the R&D researches which are also granted by TÜBİTAK, Sistem Teknik has introduced the new kind of vacuum furnaces called AIO and has added them to its product range. This vacuum furnace al- lows to make annealing, temper- ing, austempering, martempering, gas hardening, oil hardening and also low pressure carburizing inside it. The useful dimensions change from 300x500x300 mm to 900x1500x900 mm. Depending on the useful dimensions, the total material handling capacity also changes from 80 kg to 1000 kg. The working temperature range of the furnace is between 800°-1300°C and the maximum temperature can be achieved with this furnace is 1350°C. With patterned distribution of the graphite heating elements, the temperature homogeneity could be achieved as ± 5 ° C for empty furnace. With this ability, the furnace can be classified as Class II furnace with regard to AMS 2750 standard. This situation is verified with both numerical and experimental studies as illustrated below.

The hot zone temperature of the furnace is controlled by S Type thermocouples and the workpiece temperature can be monitored by multiple N type thermocouples in order to make controlled heat treat- ment. The workpiece can be cooled by either with gas or with oil. The gas cooling can be done up to 6 bar (Abs.) with nitrogen and argon. The empty furnace can be cooled down with nitrogen in less than 25 min- utes. With the directional circulation of inert gas inside the furnace with 45 kW circulation fan, homogenous cooling can be achieved. However, the heat transfer coefficient for gas quenching is not enough for hard- ening process of the thick work- pieces. In these cases, AIO furnace offers oil quenching. Thanks to the high heat transfer coefficient sup- plied by the oil quenching, the work- piece whose thickness is higher than 20 mm can be hardened. The circulation of gas and oil are care- fully designed with the help of CFD simulations as shown below. We can list the critical points as fol- lows; the opening angle for gas quenching, the area of openings on the hot-zone, the CFC insulation thickness, the workpiece pattern plan inside the hot-zone, cooling heat exchanger and circulation fan parameters are critical points.

To find out more about AIO (All in One) Vacuum Furnaces, visit our magazine now: INDUSTRIAL FURNACES 1. ISSUE